Is it possible to access nodes created with inline entity forms in Drupal 8 in a form alter hook?

Question

I am working on a Drupal site that models a Family content type with entity references to Children and Parent content types. Families are entered in a single form, and I am using the inline entity form module (IEF) to enable entry of parent and child information in the same form. My goal is to allow anonymous users to create a user account by filling out this form. Currently, I have a custom module that implements hook_form_FORM_ID_alter and adds a function to the submit action that creates a new user account and sets the owner of the outer form node (the Family node in this case):

    function myModule_form_node_family_form_alter(&$form, &$form_state, $form_id){ 
        #register function on submit as that's when the node id of the created entity is available              
        $form['actions']['submit']['#submit'][] = 'signup_submit';
    }
    function signup_submit($form, &$form_state){
        #get node id of newly created entity
        $nid = $form_state->getValue('nid');
        #create user
        $email = $form_state->getValue('field_email_address')[0]['value'];
        $user = \Drupal\user\Entity\User::create();
        $user->setEmail($email);
        $user->enforceIsNew();
        $user->setPassword(getRandomPassword());
        $user->setUsername(genUsername($nid));
        if($res){
               #set user to be owner of newly created node
               dpm("User ".$user->id()."created successfully!");
               $node = node_load($nid);
               $node->setOwner($user);
               $node->save();
        }
    }

I was hoping to do the same thing for the nodes created with IEF using a similar pattern:

function myModule_inline_entity_form_entity_form_alter(&$entity_form, &$form_state){
        $entity_form['actions']['submit']['#submit'][] = 'inline_submit';
}
function inline_submit(&$entity_form, &$form_state){
        $nid = $form_state->getValue('nid');
        dpm("nid of inline entity: ".$nid);
}

... But it doesn't seem to work. If anyone knows when the nodes are actually created and how I could access the node id's so I can change the ownership, I would be greatly appreciative!

Answer 1

I ended up finding a solution. For inline forms, the content is not actually submitted until the full form is, so I can just grab the nids from the referenced entities on the form submit hook for the outer form:

function myModule_form_node_FORM_ID_alter(&$form, &$form_state, $form_id){
        #register my on_submit callback
        $form['actions']['submit']['#submit'][] = 'myModule_form_submit';
}
function myModule_form_submit($form, &$form_state){
        $fnode = $form_state->getFormObject()->getEntity();
        #in my case the field was a multiple entity reference, so loop over each created node
        foreach($fnode->field_children->referencedEntities() as $cnode){
                # do stuff with the child node in $cnode
                $cnode->save();
        }
}